It is our purpose to continue investigating relation of hormones to growth and development. Although our main emphasis is to be in the field of steroids, we plan, when appropriate, to correlate the data with the determination of various peptide hormones particularly gonadotropins and growth hormone. During the period of growth, there develop unique experiments of nature, the study of which helps in the understanding of fundamental problems of Endocrinology and Metabolism. These experiments of nature can also suggest investigations with laboratory animals which further our comprehension of the mechanism of action of hormones. Our studies on androgens will include: Androgen receptors in the erythropoietic spleen of mice. Androgen metabolism and androgen receptors in human skin fibroblasts. Clinical investigations relating to patients with disorders of sexual differentiation including male pseudohermaphroditism, microphallus and genitalia anomalies. Our studies on cortisol will include: Glucocorticoid receptors and cortisol metabolism by human skin fibroblasts: Possible application to investigations in patients with Congenital Adrenal Hyperplasia and their parents. Distribution of H3-cortisol injected in the amniotic fluid of pregnant ewes. Rat adrenal cell cultures; effect of ACTH on corticosterone production. Our studies on aldosterone will include: Aldosterone receptors in fibroblasts from rat blood vessels. Comparison of MCR of aldosterone determined by constant infusion technique and pulse technique. Determination of the 24 hour integrated concentration of aldosterone.